Kenwood TS-890S Service Bulletin

SERVICE BULLETIN

TS-890S

Circuit update for antenna tuner failure.

A TS-890S with confirmed Antenna Tuner Unit (ATU) failure will need to be serviced at the Kenwood authorized service

center and a circuit update will be applied to reduce any possible reoccurrence of the ATU failure. This circuit update is not a

recall and is not necessary for units that have not had any ATU failures. Only a few isolated occurrences have been noted for

this failure and only units with confirmed ATU failure should have this update applied.

If a user of the TS-890S has encountered a failure of the Antenna Tuner, please ship your TS-890S to the authorized service

center for repair. Freight charges to the service center will be paid by the user and Kenwood will pay the return freight and

perform the repairs at no charge as a courtesy repair, even if the warranty is expired.

For users that have already repaired their ATU by themselves and wish to perform this update can follow these instructions

to do the circuit update. No additional parts are required and only 10 chip capacitors are being deleted from the Antenna

Tuner Unit circuit located on the Final Unit PCB (bottom side).

When a TS-890S Antenna Tuner circuit is repaired by replacing the relay control transistors part number DTD113ZU (mainly

Q510, Q511, Q512), please also remove the chip capacitors as follows to prevent recurrence of the ATU failure.

Kenwood does not recommend users of the TS-890S attempt any service of its internal components. Only qualified

technicians should attempt any internal repairs. Please ship your TS-890S to a Kenwood authorized service center

for any needed repairs. Kenwood will not be liable for any damage or injury caused by users attempting to service

the internal parts of the TS-890S. Anyone attempting to service the internal parts of the TS-890S will do so at their

own risk of causing further damage to the TS-890S or personal injury caused from the service attempt. Any

damage to the TS-890S that occurred while attempting this update will not be covered by the factory warranty or

the courtesy repair.

(Instructions)

1. Remove all power sources from TS-890 and all external connections from rear and front panels

2. Remove upper cabinet lid and RF shield to expose Final/AT Unit PCB

3. Remove Final/AT unit PCB from the chassis to expose the circuit update area on the bottom side of the

PCB

4. Remove 10 small chip capacitors shown in the following picture

5. Suggest using 2 soldering irons to avoid damage to the PCB. First apply solder on both sides of each

capacitor then use both soldering irons at the same time to heat the solder points of the capacitor and

move it from its location

6. Caution: If the capacitor is forcibly removed and the circuit trace is torn a repair will be required or the

ATU circuit will not work

7. Check area is clear of any damage and remove any solder bridges / balls

8. Re-assemble unit

9. Test ATU is operational on all bands

WSR Service Code – Information Only - No Warranty Compensation Allowed

Copyright © 2022 All Rights Reserved.

PO Box 22745

Long Beach, CA 90801

Tel 310-639-4200

ASB-0167

June 16, 2022